Process for producing a semiconductor device with a roughened semiconductor surface

1. A process for producing a semiconductor device with a roughened semiconductor surface, which comprises the following sequential steps: a) producing a semiconductor body having an Al.sub.x Ga.sub.1-x As layer with an upper surface, where x.ltoreq.0.40; b) applying a contact metallization made of a non-noble metallic material to the Al.sub.x Ga.sub.1-x As layer; c) precleaning a semiconductor surface to produce a hydrophilic semiconductor surface; d) roughening the upper surface of the Al.sub.x Ga.sub.1-x As layer by etching with an etching mixture of hydrogen peroxide.gtoreq.30% and hydrofluoric acid.gtoreq.40% (1000:6) for a period of from 1 to 2.5 minutes; and e) re-etching with a dilute mineral acid.

2. The process according to claim 1, which comprises forming the contact metallization of aluminum.

3. The process according to claim 1, which comprises forming the contact metallization of an aluminum-based alloy.

4. The process according to claim 1, which comprises additionally roughening at least sub-regions of lateral surfaces of the semiconductor body.